Tag Archives: human brain

On the one hand, a main theme hereis theories of consciousness. On the other hand, it’s been almost eight years blogging, and I’ve covered my views pretty well in numerous posts and comment threads. Our understanding of consciousness currently seems stuck pending new discoveries, either in answering hard questions, or in providing entirely new paths.

A while back I determined to step away from debates (even blogs) that center on topics with no resolution. Religion is a big one, but theories of mind is another. Your view depends on your axioms. Unless (or until) science provides objective answers, everyone is just guessing.

In Greek mythology, the hero Theseus, who slew the Minotaur and escaped its maze, returned from Crete to Athens where the Athenians preserved his ship in seaworthy state for more than a thousand years. It was an emblem of courage and a reminder of a national hero that many Greeks considered more legendary than mythological.

The Ship of Theseus was carefully maintained. Parts that rotted away were replaced with exact replicas. And in a ship made almost entirely of wood, crude iron, rope, and sail, everything rots, so eventually everything gets replaced.

A while back I realized I had an Engineer’s Mind. I’ve always had a sense of that. What I realized was the significance of the Engineer’s Mind category. And of other categories of Mind — for example an Artist’s Mind (which I didn’t discover I also had until high school; see My Life 2.0).

Having a given Mind doesn’t mean one is necessarily good at something (skill takes practice), but it does suggest a predisposition or talent for it. Our minds seem to come pre-wired in two ways: core wiring that makes us human; and “flavor” wiring that gives us (some of our) basic traits. For instance, some people have — or strongly do not to have — a Math Mind.

Over the last few weeks I’ve written a series of posts leading up to the idea of human consciousness in a machine. In particular, I focused on the difference between a physical model and a software model, and especially on the requirements of the software model.

The series is over, I have nothing particularly new to add, but I’d like to try to summarize my points and provide an index to the posts in this series. It seems I may have given readers a bit of information overload — too much information to process.

Last time we considered the possibility that human consciousness somehow supervenes on the physical brain, that it only emerges under specific physical conditions. Perhaps, like laser light and microwaves, it requires the right equipment.

We also touched on how Church-Turing implies that, if human consciousness can be implemented with software, then the mind is necessarily an algorithm — an abstract mathematical object. But the human mind is presumed to be a natural physical object (or at least to emerge from one).

The underlying question all along is whether a software model of a brain — in contrast to a physical model — can be conscious. A related, but separate, question is whether some algorithm (aka Turing Machine) functionally reproduces human consciousness without regard to the brain’s physical structure.

Last time I introduced four levels of possibility regarding how mind is related to brain. Behind Door #1 is a Holy Grail of AI research, a fully algorithmic implementation of a human mind. Behind Door #4 is an ineffable metaphysical mind no machine can duplicate.

The two doors between lead to physical models that recapitulate the structure of the human brain. Behind Door #3 is the biology of the brain, a model we know creates mind. Behind Door #2 is the network of the brain, which we presume encodes the mind regardless of its physical construction.

Last week we took a look at a simple computer software model of a human brain. (We discovered that it was big, requiring dozens of petabytes!) One goal of such models is replicating consciousness — a human mind. That can involve creating a (potentially superior) new mind or uploading an existing human mind (a very different goal).

Now that we’ve explored the basics of calculation, code (software), computers, and (computer software) models, we’re ready to explore what’s involved in attempting to model a (human) mind.

Last time we looked at the basic requirements for a software model of a computer and put a rough estimate on the size of such a model (about 2.5 terabytes). This time we’ll consider a software model of a human brain. Admittedly, there’s much we don’t know, and probably need for a decent model, but we can make some rough guesses as a reference point.

We’ll start with a few basic facts — number of neurons, number of synapses — and try to figure out some minimal requirements. The architecture of a viable software brain model is likely to be much more complicated. This is just a sketch, a Tinkertoy® or LEGO® version.